cardiac glycoside

noun

: any of several glycosides (such as digitoxin or ouabain) occurring typically in plants (such as the foxglove or squill) and acting on the heart to increase the force and rate of myocardial contraction

Although two centuries of anecdotal clinical evidence support the use of cardiac glycosides for the treatment of heart failure, controversy has surrounded their efficacy and appropriate indications.

—Thomas W. Smith, The New England Journal of Medicine